Sensors are used in numerous applications to measure different characteristics of an environment, including, but not limited to, pressure, temperature, and the like. Unfortunately, over time, sensor properties may degrade leading to less reliable measurements. This is commonly referred to as sensor drift, which can be defined as the change in the output of a transducer over time under constant input. For example, a pressure transducer exposed to a fifty (50) PSI environment may initially provide an output indicative of a measurement of fifty (50) PSI. Over time, even when exposed to the same fifty (50) PSI environment, the pressure transducer's output may change to indicate other measurements, e.g., forty-eight (48) PSI.
Sensor drift can usually be expressed as a percentage of the full scale range of a sensor. Unfortunately, sensor drift can often approach or even exceed about 0.1% or 0.2% of the sensors full scale range. This means that for a one thousand (1,000) PSI sensor, sensor drift can cause output variations greater than two (2) PSI. Therefore, sensor drift can be problematic for many applications, especially those applications where reliable sensor measurements are required.
A conventional technique for compensating for sensor drift in differential sensors—sensors measuring difference in a property, e.g., pressures at two different locations—is to zero the outputs of the sensors before they are placed into use or at various times during use. Unfortunately, this technique is useless for absolute sensors or for differential sensors that never go to zero.
Accordingly, there is a desire for improved systems and methods for compensating for sensor drift. Various embodiments of the present invention address this desire.